No matter how careful you are, you have probably deleted computer files by accident at some point. Luckily there are programs like O&O UnErase to help you.
This tool takes advantage of the fact that the system doesn't really erase a file when you delete it, even when you erase from the Recycle Bin. It simply marks the disk space used by the file up to that moment as free again, but the file still remains there.
O&O UnErase analyzes your hard drive and finds these "deleted" files and gives you the chance to recover them – though you'll have to pay for the complete version if you want to actually recover those files.
This limitation of the trial version makes this version of O&O UnErase a bit disappointing. Also, the advanced search tool doesn't include format filters (you have to manually enter the extension by yourself) and, more importantly, results are a pain to browse, all tucked in an endless list with too cryptic names.
On the positive side, O&O UnErase has quite a user-friendly interface (very similar to Windows Explorer) which makes it easy to use for all types of user.
O&O UnErase lets you recover accidentally deleted files, but only in the complete version. The trial only gives you a preview of what the program can do.